Science Story > Measurement > Teaching and Learning Approaches > How long is it?
TEACHER RESOURCE: How long is it?
This teacher resource is a collection of length measurements found in science stories and
contexts from within the Science Learning Hub. Lengths range from the very small to the very
big.
Planck length
1.6 x 10-35 m. Anything shorter than this makes no physical sense. It is the ‘quantum of length’
– the smallest measurement of length with any meaning.
Quark
10-18 m or 1 attometre (am). Quarks are the building blocks of protons and neutrons.
www.sciencelearn.org.nz/Contexts/Just-Elemental/Science-Ideas-and-Concepts/The-structureof-the-nucleus
Nucleus
10-15 m or 10 femtometres (fm). The tiny, dense central part of an atom.
www.sciencelearn.org.nz/Contexts/Just-Elemental/Science-Ideas-and-Concepts/The-structureof-the-nucleus
Gamma Ray
10-12 m or 1 picometre (pm). The wavelength of this highly energetic form of electromagnetic
radiation.
www.sciencelearn.org.nz/Science-Stories/Harnessing-the-Sun/Sci-Media/Animations-andInteractives/The-electromagnetic-spectrum
Hydrogen atom
25 pm. The approximate diameter of a hydrogen atom.
www.sciencelearn.org.nz/Contexts/Just-Elemental/Sci-Media/Images/Westpac-StadiumWellington
Carbon nanotube
10-9 m or 1 nanometre (nm). The approximate diameter of a carbon nanotube.
www.sciencelearn.org.nz/Contexts/Nanoscience/Sci-Media/Images/Carbon-nanotubes
DNA thickness
3 nm. The distance across the ‘twisted ladder’ structure of DNA.
www.sciencelearn.org.nz/Contexts/You-Me-and-UV/Sci-Media/Images/DNA-bases
HIV
90 nm in diameter. The human immunodeficiency virus (HIV) is spherical in shape.
www.sciencelearn.org.nz/About-this-site/Glossary/HIV
UVA wavelength
315–400 nm. Overexposure to ultraviolet (UV) light can damage the skin.
www.sciencelearn.org.nz/Contexts/You-Me-and-UV/Science-Ideas-and-Concepts/What-is-UV
Clay particle
10-6 m or 1 micrometre (1 m). Clay is a soft, loose, earthy material containing particles with a
grain size of less than 4 micrometres (μm).
www.sciencelearn.org.nz/Contexts/Ceramics/Science-Ideas-and-Concepts/What-is-clay
Fern spore
30–50 m. Spores are produced in capsules called sporangia. These are aggregated into
clusters called sori, found on the under surface of fern fronds.
www.sciencelearn.org.nz/Contexts/Ferns/Sci-Media/Animations-and-Interactives/Fern-structure
© 2007–2011 The University of Waikato
www.sciencelearn.org.nz
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Science Story > Measurement > Teaching and Learning Approaches > How long is it?
Naked eye limit
100 m. The smallest structure just visible to the unaided eye is about 100
www.sciencelearn.org.nz/Science-Stories/Our-Senses/Sight
m.
Human skin
0.5–4 x 10-3 m or 0.5–4 millimetres (mm). Depending on location, human skin varies in
thickness from 0.5 mm (eyelids) to 4 mm (palms and soles of the feet).
www.sciencelearn.org.nz/Science-Stories/Our-Senses/Sci-Media/Images/Diagram-of-humanskin-structure
Microwaves
10-2 m or 1 centimetre (cm). Microwaves are used for heating food in a microwave oven or for
transmitting information from one place to another.
www.sciencelearn.org.nz/Science-Stories/Tsunamis-and-Surf/Sci-Media/Images/Wavelengthsof-different-wave-types
FM radio waves (100 MHz)
Wavelength is 3 x 100 m or 3 metres (m).
www.sciencelearn.org.nz/Science-Stories/Tsunamis-and-Surf/Fundamentals-of-waves
Marathon
42.2 x 103 m or 42.2 kilometres (km). The current men’s world record for the marathon is
2:03:59. Most recreational runners would take about 4 hours to complete it.
www.sciencelearn.org.nz/Contexts/Sporting-Edge/NZ-Research/Marathon-versus-sprint
Earth’s diameter
~12.8 x 106 m or 12.8 megametres (Mm) or 12.8 thousand kilometres.
www.sciencelearn.org.nz/Contexts/Earthquakes/Sci-Media/Images/Earth-structure
Sun’s diameter
1.4 x 109 m or 1.4 gigametres (Gm).
www.sciencelearn.org.nz/Contexts/Space-Revealed/Science-Ideas-and-Concepts/Distances-inspace
Earth to Neptune distance
4.35 x 1012 m or 4.35 terametres (Tm) or 4.35 million kilometres.
www.sciencelearn.org.nz/Contexts/Space-Revealed/Science-Ideas-and-Concepts/Distances-inspace
1 light year
9.5 x 1015 m or 9.5 petametres (Pm) or 9.5 million million kilometres. The closest star system,
outside the solar system, is Alpha Centauri located about 4.37 light years away.
www.sciencelearn.org.nz/Contexts/Space-Revealed/Science-Ideas-and-Concepts/Distances-inspace
Current estimated diameter of the observable universe
~8.8 x 1026 m or 93 billion light years.
Planck length
1.6 x 10-35 m
© 2007–2011 The University of Waikato
www.sciencelearn.org.nz
1 metre
Observable universe diameter
~8.8 x 1026 m
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